Embodiments of the invention relate generally to pick tools comprising a superhard tip, particularly but not exclusively degrading hard or abrasive bodies, such as rock, asphalt, coal or concrete, for example, and to a method for making same.
Pick tools may be used for breaking, boring into or otherwise degrading structures or bodies, such as rock, asphalt, coal or concrete and may be used in applications such as mining, construction and road reconditioning. For example, in road reconditioning operations, a plurality of pick tools may be mounted on a rotatable drum and caused to break up road asphalt as the drum is rotated. A similar approach may be used to break up rock formations such as in coal mining. Some pick tools may comprise a working tip comprising synthetic diamond material, which is likely to have better abrasion resistance than working tips formed of cemented tungsten carbide material. However, synthetic and natural diamond material tends to be more brittle and less resistant to fracture than cemented carbide material and this tends to reduce its potential usefulness in pick operations. There is a need to provide a pick tool having longer working life.
United States patent application publication number 2008/0035383 discloses a high impact resistant tool having a superhard material bonded to a cemented metal carbide substrate, the cemented metal carbide substrate being bonded to a front end of a cemented metal carbide segment, which has a stem formed in the base end, the stem being press fit into a bore of a steel holder. The steel holder is rotationally fixed to a drum adapted to rotate about an axis.